The present invention relates to a sealing ring for a turbomachine, a seal for a turbomachine, a turbomachine, and a method for the manufacture of a sealing ring for a turbomachine.
Turbomachines (such as, for example, aircraft engines and stationary gas turbines) have a rotor with a plurality of rotating blades as well as a guide vane cascade or a guide vane row with a plurality of guide vanes. The guide vanes serve to optimize the flow conditions for the rotating blades; guide vanes and rotating blades are arranged in succession in the primary flow direction.
In order to seal a region between guide vanes and rotor radially inward from the flow duct, seals are commonly fastened at the radially (referred to the axis of rotation) inner-lying ends of the guide vanes or guide vane segments; the English terms “inner air seal (IAS)” or “static inner air seal (SIAS)” are also used for these seals in technical jargon. Such a seal can comprise, for example, a brush or run-in coating sealing ring (for example, a honeycomb seal), which can be arranged facing the rotor shaft at the guide vanes or guide vane segments. Preferably, the fastening is made in such a way that the seal is mounted so as to move in the radial direction relative to the guide vanes or guide vane segments and, in particular, is mounted to them in a spoke-centered manner; in this way, it is possible to take into account in the design the different thermal expansions between a guide vane ring formed from the guide vanes or guide vane segments and the brush or run-in coating sealing ring during operation of the turbomachine. Such seals are disclosed, for example, in the publications DE 196 28 559 A1 and DE 101 22 732 A1.
In addition to the brush or run-in coating sealing ring, the seals can have at least one sealing ring further outward radially, which, in each case, faces an axially adjacent rotating blade ring and reduces any radial flow between guide vanes and rotating blades.